The Cohn Cold Fractionation Process (“Cohn Process”) is generally employed in the fractionation of plasma into a number of medically useful and important protein fractions in addition to the production of albumin. The Cohn Process involves modifying the pH, ethanol concentration, and temperature to separate proteins through precipitation into five “fractions”. The separated proteins then undergo an extensive purification process that includes cryoprecipitation, nanofiltration, solvent detergent treatments, and incubation, to produce a sterile, virally inactivated protein product.
In particular, Immunoglobulin G (IgG) is a type of antibody and is a protein complex composed of four peptide chains—two identical heavy chains and two identical light chains arranged in a Y-shape typical of antibody monomers. Each IgG has two antigen binding sites. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in the circulatory system. IgG molecules are typically created and released by plasma B cells. Antibodies are major components of humoral immunity. IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection of body tissues. IgG protects the body from infection by binding many kinds of pathogens, such as viruses, bacteria, and fungi. In the plasma-derived industry, IgG is usually purified from human plasma from Fraction II. However, a certain percentage of IgG may be precipitated from Fraction III paste, which includes 34 existing and newly-found proteins, and 55 new found proteins in fractions of plasma.
Typically, Fraction IV is a discard fraction in the plasma derived products industry. It mainly contains human albumin, apolipoprotein, transferrin, alpha 1 antitrypsin haptoglobin, vimentin and new found proteins. One particular product, AFOD, contains 15 human proteins in which there are 4 new found proteins in the fractions of plasma.